Yueguang Wang’s research while affiliated with University of Idaho and other places

Three rice (Oryza sativa L.) germplasm lines designated TIL:383.13 (Reg. No. GP-144, GSOR 100605), TIL:625 (Reg. No. GP-145, GSOR 100698), and TIL:634 (Reg. No. GP-146, GSOR 100702), contain a total of seven alleles of indica rice origin associated with earlier development and increased numbers of tillers during early plant development stages in an elite US tropical japonica rice genetic background having long grain shape and intermediate amylose content and gelatinization temperature. The three high-tillering introgression lines also exhibit increased panicle number and grain yield and were jointly released in 2016 by the USDA-ARS and Texas A&M Agrilife Research. The novel alleles for enhanced tiller production originated from 'TeQing', an indica rice cultivar from China, and were transferred through a series of backcrossing into lines having a predominantly 'Lemont' genetic background. TeQing is well known in the United States for both its high yield and its disease resistance but is not suitable for commercial production due to lodging and poor grain quality. A combination of molecular and phenotypic data was used to identify these three improved germplasm lines from among 123 TeQing-into-Lemont backcross introgression lines. A combination of phenotypic and molecular data was used to select three lines from among 123 TeQing-into-Lemont backcross introgression lines. TX. Mention of a trademark or proprietary product is solely for the purpose of providing specific information and does not constitute an endorsement by the USDA nor imply approval to the exclusion of other products that may be equally suitable. The USDA is an equal opportunity provider and employer.

An increase in early tiller production is desired in rice (Oryza sativa L.) to increase yield potential and enhance ability to shade and suppress weeds. Unfortunately, tiller production and survival are sensitive to many environmental cues, making tillering pattern a difficult trait to reliably evaluate in field plots. The present objective was to use pot-grown plants where seeding depth and the environment could be controlled to identify quantitative trait loci (QTLs) associated with rate of seedling development (seedling leaf number, SLN) and tiller production (tiller number, TN) as well as the node from which the first tiller originated (N1T).The QTLs were identified in two related mapping populations, the first being a set of 280 ‘Lemont ‘TeQing’ recombinant inbred lines (RILs) observed over four trials, in which nine QTLs associated with TN, three for SLN, and two for N1T were detected. Eight of the TN QTLs were verified in a second population consisting of 123 TeQing-into-Lemont backcross introgression lines (TILs). Each SLN and N1T QTL was colocated with a TN QTL, and all nine detected TN QTLs were located in genomic regions previously reported to contain TN major genes or QTLs, demonstrating their robustness under diverse genetic backgrounds and growth conditions. Early tillering was associated with rapid seedling development as detected by an increased number of leaves and nodes on 8-wk-old seedlings. The present data indicated that breeders could effectively select for enhanced early tiller production among segregating genotypes based on tiller counts conducted at a single time point approximately 8 to 9 wk after germination under greenhouse conditions. Marker-trait linkages reported here can support marker-assisted selection of these nine TN QTLs.